Egg coffee – a mild and refreshing drink that can be served warm as well as cold

I recently stumbled over “Norwegian egg coffee”. At first I thought it was a joke, but it turned out that this is indeed an “egg coffee” – coffee prepared with an egg! I have never heard about it here in Norway, but the fact that it’s popular among Americans of Scandinavian origin in the Midwest suggests that it could be something immigrants brought with them from Norway (feel free to fill me out on the historic origins of this!). I mentioned egg coffee to my mom, and although she had never heard of it before, she did mention that skin or swim bladders from fish were used when boiling coffee to help clearify it. In fact the Norwegian name for this – klareskinn – literally means “clearing skin”. The English name is isinglass (thank’s Rob!). Could it be that the fish skin originally used was replaced by eggs, perhaps due to a limited availability of fish in the Midwest? After all, both are good protein sources.
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Ever thought about how pretzels and salt sticks get their nice brown color?

The products of the Maillard reaction provide tastes, smells and colors that are much desired and lend their charachteristics to a variety of foods. In this post I will focus on the factors that influence how fast the Maillard reaction proceeds. And more specifically I’ll give examples on how the Maillard reaction can be speeded up. This is not about fast food, nor is it about saving time. It’s more about controlling the browning reaction by speeding it up or slowing it down in order to get a desired end result.

The Maillard reaction is, to put it simple, a reaction between an amino acid and a sugar (there’s more on the chemistry at the end of the post). To speed it up you can do one or more of the following:
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By beating air into an egg white you can increase it’s volume by a factor of approximately 8. Hervé This has shown that water is the limiting component. By adding more water you can significantly increase the volume. Addition of sugar further stabilises the foam by increasing the viscosity of the water. A very simple dessert kan be made by whisking egg whites with sugar and berries of your choice. In Norway we refer to this as “Troll cream”. There’s more on this over at eriks-food-ucation.blogspot.com. An interesting question for you to ponder upon is in what order egg whites, berries and sugar should be mixed to maximize the volume!

But there is more to such a foam than trolls! For the following experiment, use one eggwhite and a berry syrup of your choice – I used a blueberry syrup (approximately 1,5 dL). Start by whisking the egg white. Add the syrup slowly over 5-10 min while constantly whisking. Observe how the volume increases dramatically. When I did the experiment I got roughly 2 L of foam (which corresponds to a 40-50 fold increase in volume). Make sure you use a clean bowl, preferably one of metal as fats and oil cling very well to plastic bowls.

Now comes the fun part: Put some of the egg white foam onto a plate and place it in a microwave oven to make the proteins set! Hervé This described this in a recent article and decided to name this dish “Vauquelin” after the french pharmacist and chemist Louis Nicolas Vauquelin. It does take some experimentation to find a proper combination of the power setting and the time needed for the Vauquelin to set. If you overdo it, the foam will just collapse. I used the 360W setting and 4 seconds for the Vaquelin in the picture below.

Cutting through the Vauquelin with a knife leaves a trace which does not refill.

Scooping out with a spoon also gives you an impression of the texture.

Instead of blueberry syrup you can try other liquids. Hervé This suggests orange juice or cranberry juice (both require addition of sugar). Liquours also work fine (although my experimentation suggests that the volume increases somewhat less), but remember to add sugar as this stabilises the foam and rounds of the taste.